White Paper

In The Best Of Light: The Challenges Of Minimum Illumination

Source: Axis Communications

Light is fundamental to the quality of an image. As a rule, provided it is not overexposed, the image will be better the more light that is available in the scene. If the amount of light is insufficient, the image will be noisy or dark. The amount of light that is required to produce a good-quality image depends on the camera and how sensitive to light it is. In other words, the darker the scene, the more sensitive to light the camera has to be.

Light sensitivity, or minimum illumination, refers to the smallest amount of light needed for the camera to produce an image of useable quality. Minimum illumination is presented in lux (lx), which is a measure of illuminance, often inappropriately referred to as light intensity. Thus, one might argue that the lower the lux rating indicated by the vendor, the more sensitive the camera. However, it is not quite that simple. There is a paradox to the minimum illumination issue. While light sensitivity is often a key deciding factor when deciding between products and vendors, it is a challenging aspect of camera technology and one of the most difficult to depict.

This paper aims to bring some nuance to the discussion on light sensitivity, to highlight the traps and explain why in-the-field testing is preferred over datasheet comparisons and necessary to make an in- formed purchase decision.